4391 has 2 divisors, whose sum is σ = 4392.
Its totient is φ = 4390.
The previous prime is 4373. The next prime is 4397. The reversal of 4391 is 1934.
Multipling 4391 by its sum of digits (17), we get a palindrome (74647).
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 4391 - 26 = 4327 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is a plaindrome in base 15 and base 16.
It is a nialpdrome in base 11.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (4397) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2195 + 2196.
It is an arithmetic number, because the mean of its divisors is an integer number (2196).
24391 is an apocalyptic number.
4391 is a deficient number, since it is larger than the sum of its proper divisors (1).
4391 is an equidigital number, since it uses as much as digits as its factorization.
4391 is an evil number, because the sum of its binary digits is even.
The product of its digits is 108, while the sum is 17.
The square root of 4391 is about 66.2646210281.
The cubic root of 4391 is about 16.3752452229.
The spelling of 4391 in words is "four thousand, three hundred ninety-one".